[PATCH v4 0/4] ACPI: LoongArch: Add IOVT table support

[PATCH v4 0/4] ACPI: LoongArch: Add IOVT table support

[Bibo Mao]

I/O Virtualization Table is ACPI table for LoongArch IOMMU devices, it
is merged on ACPI Spec 6.6, and it can be located at
  https://www.loongson.cn/uploads/images/2024110517404135188.LoongArch-IO-Virtualization-Table-Specification.pdf

Here add IOVT table parsing on LoongArch system, it is for LoongArch
IOMMU driver use in future.
---
v3 ... v4:
  1. Move kernel option ACPI_IOVT from patch 4 to patch 2.
  2. Move function call with iovt_iommu_configure_id() before function
     viot_iommu_configure() in acpi_iommu_configure_id().
  3. Rename LoongArch with LOONGARCH like other architecture in file
     MAINTAINERS.
  4. Set Huacai as one of Maintainers.

v2 ... v3:
  1. Add separate patch with header file include/linux/acpi_iovt.h,
     after it is merged in acpica tree.
  2. Modify patch set since macro name is changed in acpi_iovt.h
  3. Merge patch 1 and patch 2 together.

v1 ... v2:
  1. Reorganize the patch, patch 1/4 are merged, patch 3/5/6 are merged,
     add patch 2/8 are merged together.
  2. Enrich error printk information in iovt_get_pci_iommu_fwnode().
---
Bibo Mao (4):
  ACPICA: actbl2.h: Add bit constants of the Flags field in the IOVT
    IOMMU structure
  ACPI: LoongArch: Add acpi_arch_[late]_init()
  ACPI: scan: Add support for LoongArch in acpi_iommu_configure_id()
  MAINTAINERS: Add entry for drivers/acpi/loongarch

 MAINTAINERS                     |   9 +
 arch/loongarch/Kconfig          |   1 +
 drivers/acpi/Kconfig            |   4 +
 drivers/acpi/Makefile           |   2 +-
 drivers/acpi/bus.c              |   2 +
 drivers/acpi/loongarch/Kconfig  |   7 +
 drivers/acpi/loongarch/Makefile |   3 +
 drivers/acpi/loongarch/init.c   |  16 ++
 drivers/acpi/loongarch/init.h   |   5 +
 drivers/acpi/loongarch/iovt.c   | 280 ++++++++++++++++++++++++++++++++
 drivers/acpi/scan.c             |   3 +
 include/acpi/actbl2.h           |   7 +
 include/linux/acpi.h            |   1 +
 include/linux/acpi_iovt.h       |  13 ++
 14 files changed, 352 insertions(+), 1 deletion(-)
 create mode 100644 drivers/acpi/loongarch/Kconfig
 create mode 100644 drivers/acpi/loongarch/Makefile
 create mode 100644 drivers/acpi/loongarch/init.c
 create mode 100644 drivers/acpi/loongarch/init.h
 create mode 100644 drivers/acpi/loongarch/iovt.c
 create mode 100644 include/linux/acpi_iovt.h


base-commit: 93f51579e7df248780214094418f205253383cc5
-- 
2.39.3

[PATCH v4 1/4] ACPICA: actbl2.h: Add bit constants of the Flags field in the IOVT IOMMU structure

[Bibo Mao]

According to the IOVT specification, define macros for each bit of the
Flags field in the IOVT IOMMU structure.

Link: https://github.com/open-acpica/acpica/commit/352f750e4cc0
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 include/acpi/actbl2.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index baef525367b5..76e4a5bc79b4 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -919,6 +919,13 @@ struct acpi_iovt_iommu {
 	u32 device_entry_offset;
 };
 
+/* Masks for Flags field above */
+#define ACPI_IOVT_IOMMU_PCI_DEVICE		(1<<0)
+#define ACPI_IOVT_IOMMU_PXM_VALID		(1<<1)
+#define ACPI_IOVT_IOMMU_MAGAGE_BY_SEGMENT	(1<<2)
+#define ACPI_IOVT_IOMMU_HW_CAP_SUPPORT		(1<<3)
+#define ACPI_IOVT_IOMMU_MSI_INT_BYPASS		(1<<4)
+
 struct acpi_iovt_device_entry {
 	u8 type;
 	u8 length;
-- 
2.39.3

[PATCH v4 2/4] ACPI: LoongArch: Add acpi_arch_[late]_init()

[Bibo Mao]

LoongArch IOMMU scanning flow is similar with virtio-iommu,
there is early init and late_init. In early init function, PCI
ACS is enabled if there is IOMMU table, and late_init is called
after PCI device scanning, where IOVT table scanning function is
executed.

Here add acpi_arch_init() and acpi_arch_late_init() API on LoongArch,
function acpi_iovt_init() is to enable PCI ACS function if IOMMU device
exists in IOVT table, and function acpi_iovt_late_init() is to scan
IOVT table, add IOMMU devices.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 arch/loongarch/Kconfig          |   1 +
 drivers/acpi/Kconfig            |   4 +
 drivers/acpi/Makefile           |   2 +-
 drivers/acpi/bus.c              |   2 +
 drivers/acpi/loongarch/Kconfig  |   7 +
 drivers/acpi/loongarch/Makefile |   3 +
 drivers/acpi/loongarch/init.c   |  16 +++
 drivers/acpi/loongarch/init.h   |   5 +
 drivers/acpi/loongarch/iovt.c   | 219 ++++++++++++++++++++++++++++++++
 include/linux/acpi.h            |   1 +
 10 files changed, 259 insertions(+), 1 deletion(-)
 create mode 100644 drivers/acpi/loongarch/Kconfig
 create mode 100644 drivers/acpi/loongarch/Makefile
 create mode 100644 drivers/acpi/loongarch/init.c
 create mode 100644 drivers/acpi/loongarch/init.h
 create mode 100644 drivers/acpi/loongarch/iovt.c

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 2067d1f2ad7a..d7f8e4fec952 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -6,6 +6,7 @@ config LOONGARCH
 	select ACPI_GENERIC_GSI if ACPI
 	select ACPI_MCFG if ACPI
 	select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
+	select ACPI_IOVT if ACPI
 	select ACPI_PPTT if ACPI
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
 	select ARCH_BINFMT_ELF_STATE
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index f165d14cf61a..192e6f18eda1 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -550,6 +550,10 @@ if ARM64
 source "drivers/acpi/arm64/Kconfig"
 endif
 
+if LOONGARCH
+source "drivers/acpi/loongarch/Kconfig"
+endif
+
 if RISCV
 source "drivers/acpi/riscv/Kconfig"
 endif
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index d1b0affb844f..91584a3c1e01 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -131,6 +131,6 @@ obj-y				+= dptf/
 obj-$(CONFIG_ARM64)		+= arm64/
 
 obj-$(CONFIG_ACPI_VIOT)		+= viot.o
-
+obj-$(CONFIG_LOONGARCH)		+= loongarch/
 obj-$(CONFIG_RISCV)		+= riscv/
 obj-$(CONFIG_X86)		+= x86/
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 808c6746be14..33d752eacde3 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1465,6 +1465,7 @@ struct kobject *acpi_kobj;
 EXPORT_SYMBOL_GPL(acpi_kobj);
 
 void __weak __init acpi_arch_init(void) { }
+void __weak __init acpi_arch_late_init(void) { }
 
 static int __init acpi_init(void)
 {
@@ -1503,6 +1504,7 @@ static int __init acpi_init(void)
 	acpi_wakeup_device_init();
 	acpi_debugger_init();
 	acpi_setup_sb_notify_handler();
+	acpi_arch_late_init();
 	acpi_viot_init();
 	return 0;
 }
diff --git a/drivers/acpi/loongarch/Kconfig b/drivers/acpi/loongarch/Kconfig
new file mode 100644
index 000000000000..91ba3c35b9bf
--- /dev/null
+++ b/drivers/acpi/loongarch/Kconfig
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# ACPI Configuration for LOONGARCH
+#
+
+config ACPI_IOVT
+	bool
diff --git a/drivers/acpi/loongarch/Makefile b/drivers/acpi/loongarch/Makefile
new file mode 100644
index 000000000000..c338d3102fc1
--- /dev/null
+++ b/drivers/acpi/loongarch/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y					+= init.o
+obj-$(CONFIG_ACPI_IOVT)			+= iovt.o
diff --git a/drivers/acpi/loongarch/init.c b/drivers/acpi/loongarch/init.c
new file mode 100644
index 000000000000..e7272ee197c7
--- /dev/null
+++ b/drivers/acpi/loongarch/init.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/acpi.h>
+#include "init.h"
+
+void __init acpi_arch_init(void)
+{
+	if (IS_ENABLED(CONFIG_ACPI_IOVT))
+		acpi_iovt_init();
+}
+
+void __init acpi_arch_late_init(void)
+{
+	if (IS_ENABLED(CONFIG_ACPI_IOVT))
+		acpi_iovt_late_init();
+}
diff --git a/drivers/acpi/loongarch/init.h b/drivers/acpi/loongarch/init.h
new file mode 100644
index 000000000000..85e5197553ad
--- /dev/null
+++ b/drivers/acpi/loongarch/init.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/init.h>
+
+void __init acpi_iovt_init(void);
+void __init acpi_iovt_late_init(void);
diff --git a/drivers/acpi/loongarch/iovt.c b/drivers/acpi/loongarch/iovt.c
new file mode 100644
index 000000000000..302ca6a75905
--- /dev/null
+++ b/drivers/acpi/loongarch/iovt.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include "init.h"
+
+struct iovt_device_entry {
+	struct list_head list;
+	int start_devid;
+	int end_devid;
+};
+
+struct iovt_fwnode {
+	struct list_head list;
+	struct fwnode_handle *fwnode;
+	int flag;
+	int segment;
+	int devid;
+	int nid;
+	struct list_head ep_list;
+};
+
+/* Root pointer to the mapped IOVT table */
+static LIST_HEAD(iovt_fwnode_list);
+static DEFINE_SPINLOCK(iovt_fwnode_lock);
+
+#ifdef CONFIG_PCI
+static void __init iovt_enable_acs(struct acpi_iovt_iommu *iommu)
+{
+	static bool acs_enabled __initdata;
+
+	if (acs_enabled)
+		return;
+
+	/* IOMMU V1 only supports PCI device management */
+	if ((iommu->header.type == ACPI_IOVT_IOMMU_V1) ||
+	    (iommu->flags & (ACPI_IOVT_IOMMU_PCI_DEVICE | ACPI_IOVT_IOMMU_MAGAGE_BY_SEGMENT))) {
+		pci_request_acs();
+		acs_enabled = true;
+	}
+}
+#else
+static inline void iovt_enable_acs(struct acpi_iovt_iommu *iommu) { }
+#endif
+
+static int __init iovt_get_pci_iommu_fwnode(struct iovt_fwnode *np, u16 segment, u16 bdf)
+{
+	struct pci_dev *pdev;
+	struct fwnode_handle *fwnode;
+
+	pdev = pci_get_domain_bus_and_slot(segment, PCI_BUS_NUM(bdf), bdf & 0xff);
+	if (!pdev) {
+		pr_err("No PCI IOMMU found for segment 0x%x bdf 0x%x\n", segment, bdf);
+		return -ENODEV;
+	}
+
+	fwnode = dev_fwnode(&pdev->dev);
+	if (!fwnode) {
+		/*
+		 * PCI devices aren't necessarily described by ACPI. Create a
+		 * fwnode so the IOMMU subsystem can identify this device.
+		 */
+		fwnode = acpi_alloc_fwnode_static();
+		if (!fwnode) {
+			pci_dev_put(pdev);
+			return -ENOMEM;
+		}
+		set_primary_fwnode(&pdev->dev, fwnode);
+	}
+
+	np->fwnode = dev_fwnode(&pdev->dev);
+	if (np->flag & ACPI_IOVT_IOMMU_PXM_VALID)
+		set_dev_node(&pdev->dev, np->nid);
+	pci_dev_put(pdev);
+	return 0;
+}
+
+static int __init iovt_add_iommu(struct acpi_iovt_iommu *iommu)
+{
+	struct iovt_fwnode *np;
+	struct fwnode_handle *fwnode;
+	struct acpi_iovt_device_entry *ep;
+	struct iovt_device_entry *entry;
+	int i, ret, start_devid;
+	bool is_start = false;
+
+	np = kzalloc_obj(struct iovt_fwnode, GFP_ATOMIC);
+	if (WARN_ON(!np))
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&np->list);
+	np->flag = iommu->flags;
+	np->segment = iommu->segment;
+	if (np->flag & ACPI_IOVT_IOMMU_PXM_VALID)
+		np->nid = pxm_to_node(iommu->proximity_domain);
+
+	if (np->flag & ACPI_IOVT_IOMMU_PCI_DEVICE) {
+		np->devid = iommu->device_id;
+		ret = iovt_get_pci_iommu_fwnode(np, np->segment, np->devid);
+		if (ret) {
+			kfree(np);
+			return ret;
+		}
+
+	} else {
+		fwnode = acpi_alloc_fwnode_static();
+		if (!fwnode) {
+			kfree(np);
+			return -ENOMEM;
+		}
+
+		np->fwnode = fwnode;
+	}
+
+	/* All devices in the segment are managed by this IOMMU */
+	if (np->flag & ACPI_IOVT_IOMMU_MAGAGE_BY_SEGMENT)
+		goto skip;
+
+	INIT_LIST_HEAD(&np->ep_list);
+	ep = ACPI_ADD_PTR(struct acpi_iovt_device_entry, iommu, iommu->device_entry_offset);
+	for (i = 0; i < iommu->device_entry_num; i++) {
+		switch (ep->type) {
+		case ACPI_IOVT_DEVICE_ENTRY_START:
+			is_start = true;
+			start_devid = ep->device_id;
+			break;
+		case ACPI_IOVT_DEVICE_ENTRY_END:
+			if (!is_start)
+				break;
+
+			entry = kzalloc_obj(struct iovt_device_entry, GFP_ATOMIC);
+			if (!entry)
+				return -ENOMEM;
+
+			entry->start_devid = start_devid;
+			entry->end_devid = ep->device_id;
+			list_add_tail(&entry->list, &np->ep_list);
+			is_start = false;
+			break;
+		case ACPI_IOVT_DEVICE_ENTRY_SINGLE:
+			entry = kzalloc_obj(struct iovt_device_entry, GFP_ATOMIC);
+			if (!entry)
+				return -ENOMEM;
+
+			entry->start_devid = ep->device_id;
+			entry->end_devid = ep->device_id;
+			list_add_tail(&entry->list, &np->ep_list);
+			is_start = false;
+			break;
+		default:
+			break;
+		}
+		ep = ACPI_ADD_PTR(struct acpi_iovt_device_entry, ep, ep->length);
+	}
+
+skip:
+	spin_lock(&iovt_fwnode_lock);
+	list_add_tail(&np->list, &iovt_fwnode_list);
+	spin_unlock(&iovt_fwnode_lock);
+	return 0;
+}
+
+static void __init iovt_init_devices(struct acpi_table_header *header)
+{
+	struct acpi_iovt_iommu *iommu;
+	struct acpi_table_iovt *iovt;
+	int i;
+
+	/* Get the first IOVT node */
+	iovt = (struct acpi_table_iovt *)header;
+	iommu = ACPI_ADD_PTR(struct acpi_iovt_iommu, iovt, iovt->iommu_offset);
+	for (i = 0; i < iovt->iommu_count; i++) {
+		iovt_add_iommu(iommu);
+		iommu = ACPI_ADD_PTR(struct acpi_iovt_iommu, iommu, iommu->header.length);
+	}
+}
+
+void __init acpi_iovt_init(void)
+{
+	acpi_status status;
+	struct acpi_table_header *hdr;
+	struct acpi_table_iovt *iovt;
+	struct acpi_iovt_iommu *iommu;
+	int i;
+
+	status = acpi_get_table(ACPI_SIG_IOVT, 0, &hdr);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND)
+			pr_err("Failed to get table, %s\n", acpi_format_exception(status));
+
+		return;
+	}
+
+	iovt = (struct acpi_table_iovt *)&hdr;
+	iommu = ACPI_ADD_PTR(struct acpi_iovt_iommu, iovt, iovt->iommu_offset);
+	for (i = 0; i < iovt->iommu_count; i++) {
+		iovt_enable_acs(iommu);
+		iommu = ACPI_ADD_PTR(struct acpi_iovt_iommu, iommu, iommu->header.length);
+	}
+
+	acpi_put_table(hdr);
+}
+
+void __init acpi_iovt_late_init(void)
+{
+	acpi_status status;
+	struct acpi_table_header *hdr;
+
+	status = acpi_get_table(ACPI_SIG_IOVT, 0, &hdr);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND)
+			pr_err("Failed to get table, %s\n", acpi_format_exception(status));
+
+		return;
+	}
+
+	iovt_init_devices(hdr);
+	acpi_put_table(hdr);
+}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index ddacac812094..2a621c095b8b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1642,6 +1642,7 @@ static inline int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id,
 #endif
 
 void acpi_arch_init(void);
+void acpi_arch_late_init(void);
 
 #ifdef CONFIG_ACPI_PCC
 void acpi_init_pcc(void);
-- 
2.39.3

[PATCH v4 3/4] ACPI: scan: Add support for LoongArch in acpi_iommu_configure_id()

[Bibo Mao]

acpi_iommu_configure_id() currently supports only IORT and VIOT. Add
support for IOVT as well.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
---
 drivers/acpi/loongarch/iovt.c | 61 +++++++++++++++++++++++++++++++++++
 drivers/acpi/scan.c           |  3 ++
 include/linux/acpi_iovt.h     | 13 ++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 include/linux/acpi_iovt.h

diff --git a/drivers/acpi/loongarch/iovt.c b/drivers/acpi/loongarch/iovt.c
index 302ca6a75905..df14ce48eac6 100644
--- a/drivers/acpi/loongarch/iovt.c
+++ b/drivers/acpi/loongarch/iovt.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/acpi.h>
+#include <linux/acpi_iovt.h>
 #include <linux/pci.h>
 #include "init.h"
 
@@ -217,3 +218,63 @@ void __init acpi_iovt_late_init(void)
 	iovt_init_devices(hdr);
 	acpi_put_table(hdr);
 }
+
+static int iovt_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
+{
+	u32 sbdf;
+	struct iovt_fwnode *np;
+	struct device *aliased_dev = data;
+	u32 domain = pci_domain_nr(pdev->bus);
+	struct iovt_device_entry *entry;
+	bool found = false;
+
+	list_for_each_entry(np, &iovt_fwnode_list, list) {
+		if (domain != np->segment)
+			continue;
+
+		/* We're not translating ourself */
+		if (dev_id == np->devid)
+			return -EINVAL;
+
+		if (np->flag & ACPI_IOVT_IOMMU_MAGAGE_BY_SEGMENT) {
+			found = true;
+			break;
+		}
+
+		list_for_each_entry(entry, &np->ep_list, list) {
+			if (dev_id < entry->start_devid)
+				continue;
+
+			if (dev_id > entry->end_devid)
+				continue;
+
+			found = true;
+			break;
+		}
+
+		if (found)
+			break;
+	}
+
+	if (!found)
+		return -ENODEV;
+
+	sbdf = (domain << 16) + dev_id;
+	return acpi_iommu_fwspec_init(aliased_dev, sbdf, np->fwnode);
+}
+
+/*
+ * iovt_iommu_configure_id - Set-up IOMMU configuration for a device.
+ *
+ * @dev: device to configure
+ * @id_in: optional input id const value pointer
+ *
+ * Returns: 0 on success, <0 on failure
+ */
+int iovt_iommu_configure_id(struct device *dev, const u32 *id_in)
+{
+	if (!dev_is_pci(dev))
+		return -ENODEV;
+
+	return pci_for_each_dma_alias(to_pci_dev(dev), iovt_pci_dev_iommu_init, dev);
+}
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 163a3cccf197..827cd526a099 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/acpi.h>
 #include <linux/acpi_iort.h>
+#include <linux/acpi_iovt.h>
 #include <linux/acpi_rimt.h>
 #include <linux/acpi_viot.h>
 #include <linux/iommu.h>
@@ -1626,6 +1627,8 @@ static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 	err = iort_iommu_configure_id(dev, id_in);
 	if (err && err != -EPROBE_DEFER)
 		err = rimt_iommu_configure_id(dev, id_in);
+	if (err && err != -EPROBE_DEFER)
+		err = iovt_iommu_configure_id(dev, id_in);
 	if (err && err != -EPROBE_DEFER)
 		err = viot_iommu_configure(dev);
 
diff --git a/include/linux/acpi_iovt.h b/include/linux/acpi_iovt.h
new file mode 100644
index 000000000000..25a846b96260
--- /dev/null
+++ b/include/linux/acpi_iovt.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ACPI_IOVT_H__
+#define __ACPI_IOVT_H__
+
+#if defined(CONFIG_IOMMU_API) && defined(CONFIG_ACPI_IOVT)
+int iovt_iommu_configure_id(struct device *dev, const u32 *id_in);
+#else
+static inline int iovt_iommu_configure_id(struct device *dev, const u32 *id_in)
+{ return -ENODEV; }
+#endif
+
+#endif
-- 
2.39.3

[PATCH v4 4/4] MAINTAINERS: Add entry for drivers/acpi/loongarch

[Bibo Mao]

ACPI defines few LoongArch specific tables which need parsing code
added in drivers/acpi/loongarch. Add maintainer entries for this newly
created folder.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 MAINTAINERS | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index cc3cae2e378b..f9ae86a42dec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -347,6 +347,15 @@ S:	Maintained
 F:	drivers/acpi/riscv/
 F:	include/linux/acpi_rimt.h
 
+ACPI FOR LOONGARCH (ACPI/LoongArch)
+M:	Bibo Mao <maobibo@loongson.cn>
+M:	Huacai Chen <chenhuacai@kernel.org>
+L:	linux-acpi@vger.kernel.org
+L:	loongarch@lists.linux.dev
+S:	Maintained
+F:	drivers/acpi/loongarch/
+F:	include/linux/acpi_iovt.h
+
 ACPI PCC(Platform Communication Channel) MAILBOX DRIVER
 M:	Sudeep Holla <sudeep.holla@kernel.org>
 L:	linux-acpi@vger.kernel.org
-- 
2.39.3